Wood grinder



P. PRIEM WOOD GRINDER Filed Dec. 20. 1923 INVENTOR PAUL. PRIEM ATTORNEYS Patented July 29, 192d.

'Y narra saar-as TENT'QFF2CE..

PAUL PRIEM, 0F HEIDENHEIM-ON-'IHE-BRENZ, GERMANY, ASSIGNOR T0 AMERICAN l VOI'I'H CONTACT COMPANY, INC., O'F NEW YORK, Y., A CORPORATION 0F NEW YORK.

WOOD GRINDER.

Application filed December 20, 1923. Serial No. 681,815.

To all whom t may cof/wem.'

Be it known that I, PAUL PRIEM, a citizen of the Republic of Germany, and residing at IIeidenheim-on-the-Brenz, Germany, have invented certain new and useful Improvements in Wood Grinders, of which the following is a specification.

This invention relates to the grinding of wood into pulp used in the manufacture of paper and more particularly to improvements in the feeding device of grinders of the continuously working type. VV`The present application as also my co-pending application, Serial No. 567,778, filed June 12, 1922, relates in particular to the construction of the feeding device which is used in such grinders.

As set forth in my said co-pending apapplication it has been observed, that only the blocks which are in direct engagements with the feed devices-that is to say, only those of the sides of the wood column-are forced, against the grind stone with the de-Y sired pressure. According to the previous invention, this diiiiculty is overcome by increasing the feed pressure on the interior of the charge by increasing the lateral pressure of the feed devices against the sides of the block mass. In this way, the grip of the feeders on the sides of the charge is transmitted to the interior of the mass, and the latter is forced against the grinder with the same pressure as the marginal areas thereof.

A new way of accomplishing this is represented in the accompanying drawing in which is shown a feed device of a special design.

Referring to the figure, Ihave indicated a pair of chains with links 1, having each the form of a wedge block with its yinclined.

surface toward the stone 4. Near the stone 4, the chains are driven in a well known manner by sprockets 3' fastened each to aV shaft 2. The chains are endless and carried by similar sprockets (not shown in the drawing) at the upper portion of the hopper. The feeding device is operated by turning the shafts 2 in the sense of the arrows.` i

I/Vith this design, the above mentioned increasing of the inwardb pressure is attained-by the fact, that, when/the chains are moving toward the stone in excess Vof the rate of consumption of the wood, the wood blocks l5, 6, 7 and 8, 9, 10 f.l i. glide into the respective' positions 51, 61, 71, and 81, 91, 101, thereby increasing the pressure in the interior of the wood column. At the same time the internal friction of the charge, is also increased with the result that the wood blocks in the middle of the hopper are pressed against the grinding surface with the same force as the marginal blocks.

Although a certain specific form of ap-Y paratus has been described, it is to be clearly understood, that the invention is not limited to these details of construction and that suitable changes may be made without de parting from the spirit of the invention.

I claim:

1. A wood grinder of the continuously working type comprising the combination of a grinding element and endless feed chains for `positively feeding a charge of wood blocks against the stone, said feed chains consisting of wedge shaped links with their inclined surfaces directed toward the stone. f

2. A' wood grinder of the continuously working type comprising the combination of a grinding element, endless feed chains for positively feeding a charge of wood blocks against the stone, said feed chains consisting of wedgeshaped links with their inclined surfaces directed toward the stone and means for moving the feed chains in excess of the rate of consumption of the wood blocks.

3. In a wood grinder, feed means forfadvancing a charge of wood blocks toward `the grind stone and' comprising a wedge member laterally applied'to the charge and adapted for sliding engagement therewith,

together with means for driving said wedge memberV toward the stone ata speed in excess of the consumption ofthe charge by the stone to cause slip between the wedge the stone to cause slip between said wedge members and the charge, and a resulting lateral oompaoting of the ohargeyas it approaches the stone.

5. The method of feeding a charge in a 5 Wood grinder Which consists in applying Wedge feed means laterally to the charge,

and causing slip between said feed means and the charge to compact the lattei` as the feed means advances toward the stone.

In testimony that I claim the foregoing 10 as my invention, I have signed my name hereunder.

PAUL PRIEM. 

